How to handle ``on("message"`` for both binary and json messages

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Issue

Hello,

I’m having an issue where I’m sending both json strings as well as flatbuffer/uin8 arrays to my websocket connection.

In on("message" I’m calling toString but that doesnt work for the Uint8Arrays being sent. How should I handle both message types / is there a flag to enable?

Current version: 4.2.2

error when calling toString on a message that is actually an Uint8Array

SyntaxError: Unexpected token ¶ in JSON at position 0
    at JSON.parse (<anonymous>)
    at C:\git\needle-tiny-networking-package\packages\websocket\src\networking.js:52:28
    at WebSocket.<anonymous> (C:\git\needle-tiny-networking-package\packages\websocket\src\proxy.js:31:17)
    at WebSocket.emit (events.js:388:22)
    at Receiver.receiverOnMessage (C:\git\needle-tiny-networking-package\packages\websocket\node_modules\fastify-websocket\node_modules\ws\lib\websocket.js:1137:20)
    at Receiver.emit (events.js:376:20)
    at Receiver.dataMessage (C:\git\needle-tiny-networking-package\packages\websocket\node_modules\fastify-websocket\node_modules\ws\lib\receiver.js:513:14)
    at Receiver.getData (C:\git\needle-tiny-networking-package\packages\websocket\node_modules\fastify-websocket\node_modules\ws\lib\receiver.js:446:17)
    at Receiver.startLoop (C:\git\needle-tiny-networking-package\packages\websocket\node_modules\fastify-websocket\node_modules\ws\lib\receiver.js:148:22)
    at Receiver._write (C:\git\needle-tiny-networking-package\packages\websocket\node_modules\fastify-websocket\node_modules\ws\lib\receiver.js:83:10)
    at writeOrBuffer (internal/streams/writable.js:358:12)
    at Receiver.Writable.write (internal/streams/writable.js:303:10)
    at Socket.socketOnData (C:\git\needle-tiny-networking-package\packages\websocket\node_modules\fastify-websocket\node_modules\ws\lib\websocket.js:1231:35)
    at Socket.emit (events.js:376:20)
    at addChunk (internal/streams/readable.js:309:12)
    at readableAddChunk (internal/streams/readable.js:284:9)

[climba03003]

socket.onmessage is made for Web API compatibility, so it returns the Event like object. https://github.com/websockets/ws/blob/master/lib/event-target.js#L193-L200

socket.on('message') is the actual Node EventEmitter implementation. It receive the raw data (e.g. Buffer, ArrayBuffer, etc).

The ws document already give you the hint on how to handle your case.

socket.on('message', function(data, isBinary) {
  // it is sent with binary
  if(isBinary) {
    const buf = Buffer.from(data)
  } else {
    const json = JSON.parse(Buffer.from(data).toString())
  }
})

[marwie]

@climba03003 thanks for explaining! that’s probably what I was missing 😃